JP2015131106A - catheter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a catheter having improved push-in force without complicating configurations of an outer tube and an inner tube.SOLUTION: A polymer is applied to a core wire 170 to increase friction force of the core wire 170 and tubes 132 and 133, or the core wire 170 and the tubes 132 and 133 are welded and, when the core wire 170 is pushed in a distal side, accordingly, the tubes 132 and 133 are pushed in the distal side. This configuration can provide a balloon catheter with improved push-in force without complicating the configurations of the outer tube 132 and the inner tube 133.

Description

  The present invention relates to a catheter having a cored bar member.

  Among catheters, for example, a balloon catheter is widely used as a medical instrument for expanding blood vessel stenosis and improving blood flow on the peripheral side of a blood vessel when stenosis occurs in a blood vessel such as a blood vessel. When performing a procedure using a balloon catheter, first, the balloon catheter is inserted into the blood vessel so that the balloon matches the stenotic site. Next, the stenotic site is expanded by injecting a pressurized fluid into the balloon to expand the balloon. After performing dilatation treatment, the balloon is deflated and the balloon catheter is removed from the blood vessel.

  In the balloon catheter, basically, a hub, a proximal shaft, and a distal shaft are arranged in this order from the proximal side (hand side), and a balloon is arranged near the tip on the distal side of the distal shaft. The proxy shaft is composed of an outer tube, and the distal shaft has a double tube structure composed of an outer tube and an inner tube. The outer tube plays a role of feeding fluid into the balloon. A guide wire is inserted through the inner tube, whereby the guide wire protrudes toward the distal end side of the balloon.

  Here, the shaft of the balloon catheter needs to be flexible enough to bend easily along a bent or meandering blood vessel, and to have a pushing force to push the balloon to the stenosis site. More specifically, a certain degree of rigidity is required near the proximal end, while high flexibility is required at the distal end.

  One way to meet these requirements is to make the shaft material harder on the proximal side and softer toward the distal side. However, since it is not easy to manufacture a shaft made of such a material, conventionally, there is one in which a change in hardness is given to the shaft by providing a core wire along the longitudinal direction of the shaft. In other words, by providing a core wire in the shaft that becomes thinner toward the tip side (distal side), it has a certain degree of rigidity on the proximal side (hand side) and is flexible toward the distal side (tip side). It is possible to realize a shaft with increased performance.

  Furthermore, conventionally, a configuration for further improving the pushing force of the shaft has been proposed.

  Patent Document 1 discloses a configuration in which the pushing force of the shaft is increased by making the base side shaft (corresponding to the outer tube) and the tip side shaft (corresponding to the inner tube) abut in the pushing direction. Has been.

  Patent Document 2 discloses a configuration in which the pushing force of the shaft is increased by forming a catheter shaft (corresponding to an outer tube) and a core wire into a shape that abuts in the pushing direction.

JP 2006-187315 A JP 2012-20077 A

  By the way, in the configurations disclosed in Patent Document 1 and Patent Document 2, the pushing force is improved in Patent Document 1 in terms of a base side shaft (corresponding to an outer tube) and a tip side shaft (corresponding to an inner tube). The effect of improving the pushing force distal to the contact portion is small. Similarly, in Patent Document 2, the pushing force is improved up to the contact portion between the catheter shaft (corresponding to the outer tube) and the core wire, and the effect of improving the pushing force distal to the contact portion is improved. Is small. Therefore, the pushing force distal to the contact portion (near the guide wire insertion port) is insufficient, and it may be difficult to make the balloon portion reach the lesioned portion.

  In addition, it is not easy to accurately manufacture the shapes of the outer tube, the inner tube, and the core shaft that have a very small cross section in the direction perpendicular to the pushing direction so as to contact each other in the pushing direction.

  The present invention has been made in consideration of the above points, and provides a catheter with improved pushing force without complicating the configuration of the outer tube and the inner tube.

One aspect of the catheter of the present invention is:
An outer tube,
An inner tube disposed in the outer tube;
A linear core member disposed between the inner surface of the outer tube and the outer surface of the inner tube;
Have
The core metal member is coated with a coating material.

One aspect of the catheter of the present invention is:
An outer tube,
An inner tube disposed in the outer tube;
A linear core member disposed between the inner surface of the outer tube and the outer surface of the inner tube;
Have
The inner surface of the outer tube and / or the outer surface of the inner tube are coated with a coating material.

  According to the present invention, a balloon catheter with improved pushing force can be realized without complicating the configuration of the outer tube and the inner tube.

Schematic which shows the whole structure of the balloon catheter which concerns on embodiment Sectional view of the balloon catheter shaft Sectional drawing of the shaft part of the balloon catheter of Embodiment 2. FIG. It is sectional drawing with which it uses for description of a welding part, FIG. 4A is a figure which shows the state before welding, FIG. 4B is a figure which shows the state after welding Sectional drawing for demonstrating the structure of Embodiment 3. FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

<Embodiment 1>
FIG. 1 is a schematic diagram showing the overall configuration of a balloon catheter according to an embodiment of the present invention. The balloon catheter 100 includes a hub 110, a balloon 120, a proxy shaft 130, and a distal shaft 140 as main bodies.

  A guide wire insertion port 150 for inserting the guide wire 160 is formed at the boundary between the proxy shaft 130 and the distal shaft 140. The proxy shaft 130 is mainly composed of an outer tube. The distal shaft 140 is mainly composed of an outer tube and an inner tube. Specifically, the proxy shaft 130 has a single tube structure with an outer tube, and the distal shaft 140 has a double tube structure with an outer tube and an inner tube. These configurations will be described in detail later with reference to FIG.

  The hub 110 is placed at the hand of a doctor who operates the balloon catheter 100 in angioplasty. The hub 110 is configured to be connectable to a pressure application device (not shown) such as an indeflator that supplies and discharges fluid by pressure. The proximal shaft 130 is joined to the hub 110 so as to be in fluid communication, and extends distally. Further, a distal shaft 140 is joined to the distal side so as to be in fluid communication. A balloon 120 is joined to the distal side of the distal shaft 140. The proxy shaft 130 and the distal shaft 140 have a flow path for supplying high-pressure fluid into the balloon 120.

  FIG. 2 shows a cross-sectional view of the shaft portion of the balloon catheter 100 cut in the longitudinal direction. The proxy shaft 130 is configured by joining an outer tube 132 to a metal tube 131. As a material of the outer tube 132, a polyamide-based resin, a urethane-based resin, or a polyethylene-based resin can be used.

  The distal shaft 140 has a double tube structure in which an inner tube 133 is disposed in a tube of the outer tube 132. The inner tube 133 is for inserting the guide wire 160 (FIG. 1). The inner tube 133 extends from the boundary position between the proximal shaft 130 and the distal shaft 140 to a position further to the distal side than the balloon 120 so as to penetrate the inside of the outer tube 132 and the balloon 120. Thereby, the guide wire 160 inserted from the guide wire insertion port 150 passes through the inner tube 133 and protrudes from the guide wire insertion port 151. As a material for the inner tube 133, a polyamide-based resin, a urethane-based resin, or a polyethylene-based resin can be used similarly to the outer tube 132.

  The proximal end of the balloon 120 is joined to the distal end of the outer tube 132, and the distal end of the balloon 120 surrounds the outer circumferential surface of the inner tube 133 and is joined to the outer circumferential surface thereof. As a result, the high-pressure fluid supplied into the outer tube 132 via the hub 110 (FIG. 1) flows into the balloon 120 through the outer tube 132 and stays in the balloon 120. As a result, the balloon 120 120 expands. The balloon 120 is folded to approximately the same size as the outer diameter of the distal shaft 140 before the high-pressure fluid is supplied to the inside. When the high-pressure fluid is supplied to the inside of the balloon 120, the balloon 120 expands by expanding the fold. 1 and 2 show a state where the balloon 120 is expanded.

  A metal core wire 170 is provided in the outer tube 132. The proximal end of the core wire 170 is joined to the metal tube 131 by welding. The length of the core wire 170 is selected so that the distal end (tip) thereof is positioned in front of the balloon 120 of the distal shaft 140. As can also be seen from the figure, the core wire 170 is disposed in the distal shaft 140 between the inner tube 133 and the outer tube 132, that is, between the outer surface of the inner tube 133 and the inner surface of the outer tube 132. .

  The core wire 170 has a shape that becomes thinner from the proximal end (proximal end) to the distal end (distal end). Thereby, the rigidity in the direction perpendicular to the longitudinal direction of the core wire 170 gradually decreases as it goes from the proximal end (proximal end) to the distal end (distal end). As a result, the balloon catheter 100 can prevent kink and buckling of the catheter without abrupt changes in rigidity at the distal end portion of the metal tube 131 while maintaining the flexibility of the distal end of the catheter.

  In addition to such a configuration, the core wire 170 is coated with a coating material. As the coating material, a material in which the friction coefficient between the coated core wire 170 and the outer tube 132 is larger than the friction coefficient between the core wire 170 and the outer tube 132 before coating is used. In the present embodiment, urethane resin or epoxy resin is used as the coating material.

  In the above configuration, when the balloon catheter 100 is inserted into a blood vessel, the shafts 130 and 140 bend along the blood vessel. When the shafts 130 and 140 are bent along the blood vessel, the core wire 170 comes into contact with the inner surface of the outer tube 132 and the outer surface of the inner tube 133. At this time, since the core wire 170 has a coefficient of friction between the inner surface of the outer tube 132 and the outer surface of the inner tube 133 increased by the coating material, the shafts 130 and 140 are moved distally while suppressing buckling of the outer tube 132. Can be pushed to the side.

  Here, in practice, in order to advance the shafts 130 and 140 in the blood vessel, the smaller the curvature of the bending shafts 130 and 140 is, the greater the resistance received from the blood vessel is. Therefore, a large pushing force is required. As the curvature of the shafts 130 and 140 decreases, the force with which the core wire 170 contacts the outer tube 132 also increases, so that a large frictional force can be obtained and a larger pushing force can be obtained. In the present embodiment, paying attention to this point, the core wire 170 is coated with a coating material that increases the coefficient of friction with the outer tube 132, so that the friction force between the core wire 170 and the outer tube 132 is positively applied. Used. Thus, a larger pushing force can be obtained under a situation where a large pushing force is required (that is, under a situation where the curvature of the shafts 130 and 140 is small).

  In addition, when the shafts 130 and 140 are bent along the blood vessel, the core wire 170 and the outer tube 132 are formed by the resistance of the blood vessel wall when the shafts 130 and 140 are advanced in the blood vessel, for example. Even when bent, it abuts. In the configuration of the present embodiment, also in this case, a large frictional force is generated between the core wire 170 and the outer tube 132 as compared with the conventional case, so that the core wire 170 pushes the outer tube 132 by the frictional force, You can move forward.

  In FIG. 2, the distal end of the core wire 170 is separated from the inner wall of the outer tube 132, but the distal end of the core wire 170 may be in contact with the inner wall of the outer tube 132. In this way, even when the tube is not bent, that is, when the tube is straight without being bent, the outer tube 132 can be given a pushing force due to friction with the core wire 170.

  As described above, according to the present embodiment, the coating of the core wire 170 with the coating material that increases the frictional force with the outer tube 132 complicates the configuration of the outer tube 132 and the inner tube 133. Therefore, the balloon catheter 100 with improved pushing force can be realized.

  Further, in the present embodiment, the pushing force can be improved up to the tip portion of the core wire as long as the core wire 170 is present, so that the pushing force on the distal side can be improved particularly compared to the conventional case. That is, as described above, in Patent Document 1, the pushing force is improved up to the contact portion between the base side shaft (corresponding to the outer tube) and the tip side shaft (corresponding to the inner tube). No. 2 is the contact portion between the catheter shaft (corresponding to the outer tube) and the core wire, and the effect of improving the pushing force on the distal side of these contact portions is small. However, according to the configuration of the present embodiment, the pushing force on the distal side can be improved as compared with the conventional case.

<Embodiment 2>
FIG. 3, which shows the parts corresponding to those in FIG. 2 with the same reference numerals, shows the configuration of the balloon catheter of the present embodiment. In the balloon catheter 200 of the present embodiment, the core wire 170 is welded to the tubes 132 and 133 at the welded portion 210 as compared to the balloon catheter 100 (FIG. 1) of the first embodiment. As a result, the metal tube 131, the core wire 170, and the tubes 132 and 133 are connected to each other, and if the metal tube 131 is pushed in, the tubes 132 and 133 can also be pushed in via the core wire 170.

  The core wire 170 is coated with a resin that is easily welded to the material of the tubes 132 and 133 (in this embodiment, a polyamide resin). In the present embodiment, polytetrafluoroethylene or polyether block amide copolymer is used as the coating material. The coating material is welded to the outer tube 132 and the inner tube 133 by pressurizing the outer tube 132 while applying heat from the outside of the outer tube 132. In the case of the present embodiment, the tip portion of the core wire 170 is welded.

  FIG. 4 is a diagram for explaining the welding. FIG. 4 shows an A-A ′ cross section of FIG. 3. FIG. 4A shows a state before welding, and FIG. 4B shows a state after welding. As shown in FIG. 4B, the core wire 170 is sandwiched between the inner tube 133 and the outer tube 132 by applying pressure to the outer tube 132 while applying heat to deform the outer tube 132 in the direction of the inner tube. In addition, the coating material is melted by heat to form the welded portion 210, and the core wire 170 is welded to the inner tube 133 and the outer tube 132.

  Further, it is preferable to use a coating material having a melting point lower than that of the outer tube 132. In the present embodiment, a polytetrafluoroethylene or polyether block amide copolymer having a melting point lower than that of the polyamide resin used as the material of the outer tube 132 is used as the coating material. By doing in this way, the welding part 210 by a coating material can be formed, suppressing the damage by the heat | fever with respect to the outer tube 132. FIG.

  As described above, according to the present embodiment, since the core wire 170 is welded to the tubes 132 and 133, the pushing force can be increased as compared with the case of using friction as in the first embodiment. .

<Embodiment 3>
In the first embodiment, the case where the core wire 170 is coated with a coating material that increases the frictional force with the outer tube 132 has been described. However, in the present embodiment, the inner surface of the outer tube 132 and / or the inner tube 133 It is presented that the outer surface is coated with a coating material that increases the frictional force with the core wire 170.

  FIG. 5 shows the configuration. FIG. 5 shows a cross section taken along the line A-A ′ of FIG. 2. A coating material 132 a is attached to the inner surface of the outer tube 132, and a coating material 133 a is attached to the outer surface of the inner tube 133. For example, a urethane resin or an epoxy resin may be used as the coating materials 132a and 133a. However, the urethane resin or the epoxy resin used as the coating materials 132a and 133a has a characteristic that the coefficient of friction with the core wire 170 increases after coating as compared with the material used for the outer tube 132 and the inner tube 133. . In the example of FIG. 5, the case where the coating materials 132 a and 133 a are provided on both the inner surface of the outer tube 132 and the outer surface of the inner tube 133 has been described, but either the inner surface of the outer tube 132 or the inner tube 133 is provided. Only the coating material may be provided. Further, the core wire 170 may be provided with a coating material.

  According to the present embodiment, the balloon catheter 100 with improved pushing force can be realized without complicating the configuration of the outer tube 132 and the inner tube 133 as in the first embodiment.

<Other embodiments>
In the above-described second embodiment, the case where the tip portion of the core wire 170 is welded has been described. However, a portion other than the tip portion of the core wire 170 may be welded. However, it is preferable to weld the tip portion of the core wire 170 because the pushing force can be improved up to the tip portion of the core wire 170. In addition, the core wire 170 may be welded over the entire length direction. However, in this case, the flexibility of the shafts 130 and 140 may be impaired. Therefore, only a part of the core wire 170 is used as in the embodiment. It is preferable to weld.

  In the above-described embodiment, the core wire 170 is used as a linear cored bar member disposed between the inner surface of the outer tube 132 and the outer surface of the inner tube 133, and one end of the core wire 170 is welded to the metal tube 131. However, the present invention is not limited to this, and the metal tube 131 itself may be thinned toward the distal side and used instead of the core wire 170. Then, the core metal member may be coated as in the embodiment.

  In the above-described embodiment, the case where the present invention is applied to a balloon catheter has been described. However, the present invention is not limited to this, and a catheter having a cored bar portion provided in the shaft over the longitudinal direction of the shaft. Widely applicable to. The present invention can be applied to, for example, a catheter used for IVUS (intravascular ultrasound), a catheter used for vascular endoscopy, and the like.

  Furthermore, in the above-described embodiment, the case where the present invention is applied to a double-tube catheter made up of an outer tube and an inner tube has been described. Is also applicable.

  The above-described embodiments are merely examples of implementation in carrying out the present invention, and the technical scope of the present invention should not be construed as being limited thereto. That is, the present invention can be implemented in various forms without departing from the gist or the main features thereof.

  The present invention can be applied to a catheter having a cored bar member.

100, 200 Balloon catheter 110 Hub 120 Balloon 130 Proximal shaft 131 Metal tube 132 Outer tube 133 Inner tube 140 Distal shaft 150 Guide wire insertion port 160 Guide wire 170 Core wire 210 Welded portion

Claims (9)

An outer tube,
An inner tube disposed in the outer tube;
A linear core member disposed between the inner surface of the outer tube and the outer surface of the inner tube;
Have
The core member is coated with a coating material;
catheter. An outer tube,
An inner tube disposed in the outer tube;
A linear core member disposed between the inner surface of the outer tube and the outer surface of the inner tube;
Have
The inner surface of the outer tube and / or the outer surface of the inner tube are coated with a coating material,
catheter. As the coating material,
A material is used in which the coefficient of friction between the cored bar member after coating and the outer tube is larger than the coefficient of friction between the cored bar member before coating and the outer tube,
The catheter according to claim 1. As the coating material,
The coefficient of friction between the outer tube and / or inner tube after coating and the cored bar member is greater than the coefficient of friction between the outer tube and / or inner tube before coating and the cored bar member. A material that grows is used,
The catheter according to claim 2. The cored bar member is welded to the outer tube by the coating material,
The catheter according to claim 1. The coating material has a lower melting point than the outer tube,
The catheter according to claim 5. The coating material is a polymer;
The catheter according to any one of claims 1 to 6. The coating material is urethane resin, epoxy resin, polytetrafluoroethylene or polyether block amide copolymer,
The catheter according to any one of claims 1 to 7. The catheter is a balloon catheter;
Fluid is sent into the balloon using the outer tube,
A guide wire is inserted through the inner tube.
The catheter according to any one of claims 1 to 8.